Human Type-IV collagen ELISA Kit

Collagen is the most abundant protein in the human body, mainly found in human skin, cartilage, tendon, heart and other parts of the body, with the function of maintaining the structural stability of tissues and organs, but also an important raw material and stabilising component in various tissue structures. The structure of collagen is formed by 3 alpha peptide chains of left-handed helical structure entwined in parallel, right-handed helical form with hydrogen bonds binding to each other, thus it has a strong tensile strength. Where the amino acids of the right-handed complex helical structural segment have a repeating sequence of (Glycine (Gly)-X-Y)_n, with X and Y usually being proline and hydroxyproline. One in every three amino acid residues must pass through the central region of the triple helix, where the space is so narrow that only Gly can enter, which is why every other amino acid residue in its amino acid composition is Gly. The specific, stable structure of collagen is the basis for its widespread use as a biomaterial.

There are numerous types of collagens, which can be classified as Type I, Type II, Type III collagen, etc., based on the order of discovery. On the basis of structural complexity, it can be divided into fibrillar and non-fibrillar collagen. Non-fibrillar collagen can be further divided into various subtypes. Among them, type IV collagen is an important component of tissues such as the basement membrane, and plays an important role in the assembly and stabilization of the basement membrane. Type IV collagen is associated with a number of inherited or acquired disorders affecting multiple organs and tissues throughout the body including the kidneys, cochlea, eye, and smooth muscle.

A total of six type IV collagen isoforms (α1-α6) have been identified, encoded by the COL4A1-A6 genes. Different subtypes of type IV collagen have different affinity and characteristic recognition sites for the C-terminal non-collagenous (NC1) domain, resulting in the formation of three highly specific triple-helical protomers, α1α1α2, α3α4α5, and α5α5α6, which are secreted extracellularly. Head-to-head connections occur between the NC1 domains of the secreted protomers, forming a lattice-like collagen network that assembles into the basement membrane.

Figure 1. The formation of collagen IV scaffolds
(Source: Ivanov SV, et al. 2021)

Type IV collagen
Collagen IV